/**
 * storage 封装
 */
const STORAGE_KEY = 'mall'

export default {
    // 存值
    setItem(key, value, module_name) {
        if (module_name) {
            let val = this.getItem(module_name)
            val[key] = value
            this.setItem(module_name,val)
        } else {
            let val = this.getStroage()
            val[key] = value
            window.sessionStorage.setItem(STORAGE_KEY, JSON.stringify(val))
        }
    },
    // 获取某一个模块下面得属性
    getItem(key,module_name) {
        if(module_name) {
            let val = this.getItem(module_name)
            if (val) return val[key]

        }
        return this.getStroage()[key]
    },
    getStroage() {
        return JSON.parse(window.sessionStorage.getItem(STORAGE_KEY) || '{}');
    },
    clear(key, module_name){
        let val = this.getStorage();
        if (module_name){
          if (!val[module_name])return;
          delete val[module_name][key];
        }else{
          delete val[key];
        }
        window.sessionStorage.setItem(STORAGE_KEY, JSON.stringify(val));
      }
}